Folding table with spring lock



I March 24, 1959 E. 1. BULLOCK FOLDING TABLE WITH SPRING LOCK 2 Sheets-Sheet 1 Filed Feb. 27', 1957 I NVEM-rOR EDWIN I. BULLOCK ATTORNEY 2 Sheet-Sheet 2 Filed Feb. 27, 1957 FIGS, I

in m if ll "W478 2 2 l I I I l r 8 Wh k 4 a w o I 4 Uh K I U JT\ B 5 G H C jfl m M a F 4 m w v W M? w k ArrguzY United States Patent FOLDING TABLE WITH SPRING LOCK Edwin I. Bullock, Solihnll, England Application February 27, 1957, Serial No. 642,892

6 Claims. (Cl. 311-87) The present invention has reference to trays, tables and like articles of furniture of the kind wherein a loadsupporting top is provided, at each of two opposed edges, with a pair of pivoted and interconnected legs, each pair being adapted to be swung between an erect position in which the legs are at right angles, or substantially at right angles, to the top, and a folded position in which the two legs lie against and along the underside of the top, and wherein manually operated devices are provided for locking each pair of legs in either of the said alternative positions.

In furniture of this kind, it is known to provide each pair of legs with a locking device which comprises two spring-loaded plungers which are retractable against the action of their respective springs by links which are connected to a common operating member so that both links and plungers are actuated simultaneously and in unison for locking or releasing the corresponding pair of legs.

The principal object of the present invention is to provide new or improved locking devices for an article of furniture of the kind hereinbefore referred to, whereby when either pair of legs is locked in either of the two alternative positions, its rigidity relative to the loadsupporting top is assured and, when both pairs of legs are locked in their erect positions, the said top is held steadily.

A further object of the invention is to provide an improved construction of load-supporting top whereby, whilst manufacturing costs are reduced to a minimum, the strength and appearance of the said top are enhanced.

In accordance with the said invention, the locking device for each leg comprises a bolt which is axially displaceable into and out of engagement with a correspondstood and carried into practice, reference will now be made to the accompanying drawing, wherein:

Figure 1 is a perspective view of a tray or table showing both pairs of legs erected.

Figure 2 is an underside plan of the tray or table showing one pair of legs erected and the other pair folded on to the underside of the load-supporting top.

Figure 3 is a section, on an enlarged scale, along the line a-a of Figure 2, a part having been removed for the sake of clarity.

Figure 4 is a section, on a still larger scale, along the line b-b, Figure 2, and Figure 5 is a section along the line 0-0, Figure 4.

The tray or table shown in the drawings, comprises a load-supporting top of which a substantially rectangular frame 1 has a sheet 2 applied to its upper edge, the sheet being retained in position by engagement of its-marginal portions with grooves 3 formed in and along the internal ing keeper place on the load-supporting top and is loaded by a spring tending to drive it into engagement with the plate, the two bolts of each pair of legs being linked to separate manually operable levers which are pivoted upon across-rail fixed to and between the legs and are moveable relatively to one another about their pivotal connections to the said rail.

Preferably, one of the levers is formed or provided with an operating handle and the other lever is formed or provided with a projection which is located in the path of travel of the handle when the latter is displaced manually for withdrawing the corresponding bolt against spring action so that, during manual bolt-withdrawing displacement, the handle abuts the projection and drives the said other lever in the bolt withdrawing direction, the projection being spaced from the handle after the two bolts have been spring-driven into locking engagement with their corresponding keeper plates, by a distance such that the handle-actuated bolt is withdrawn from engagement with the corresponding keeper plate before theother bolt, whereas, during the spring-driven return movements of the bolts the said other bolt makes locking engagement with its keeper plate before the handleactuated bolts.

. In order that the invention may be more readily undersurfaces of strips 4 secured to and lengthwise of the external surface of the frame, the said strips being deeper than the said frame so that they project upwardly of the sheet. The frame, sheet and strips are fabricated from multi-ply plywood and wooden blocks 5, 6 are fixed within the curved corners of the frame, the blocks 5 in two of the diagonally opposite corners being wider than the other two blocks 6.

One pair of legs 7 is pivotally assembled to and between the blocks 5, 6 in one end of the frame and a second pair of legs 8 is assembled to and between the blocks in the opposite end of the frame. The upper ends of the legs of each of the said pairs are interconnected by a cross rail 9 and each of the said leg ends is embraced by a U-shaped metal bracket 10 of which the base spans the side of the leg remote from the rail 9 and the two sides embrace and project beyond the leg end so that they also embrace the adjacent extremity of the rail. A pivot pin 11 provided on and externally of the base of each bracket engages a hole 12 pressed out of that arm of an angle-shaped metal keeper plate 13 which seats upon the flat face of the adjacent block 5 or 6 and which is provided on its upper edge with an outwardly extend ing ear 14 projecting between the block and the underside of the sheet 2. A peripheral flange or skirt 12a provided around the hole fits within a recess 12b in the corresponding block 5 (or 6). The other arm of the keeper plate seats upon the internal surface of the adjacent end of the frame and is provided on its upper and lower edges respectively, with outwardly extending ears 15, 16 the ear 15 projecting between the rail end and the sheet 2 and the other ear 16 abutting the lower edge of the frame end.

A recess 17 of which the mouth is covered by a panel 17a is formed in the inner surface of each rail 9 and two levers 18, 19 are pivotally mounted upon the base of the recess by screw or equivalent expedients 20, 21 respectively. The free end of the lever 18 is formed into a U-shaped handle 22 which projects below the rail and of which one side engages a longitudinal slot 23 in the lower rail edge (see Figure 2). The levers are adapted respectively to actuate spring-loaded bolts 24, 25 each of which extends through a longitudinal passage 27 (see Figure 4) in the rail and leg, and is loaded by bracket 10, into engagement with one or other of two holes 31, 32 (see Figure 5) in that arm of the keeper plate which seats upon the block 5 (or 6), depending .on whether the corresponding pair oflegs is in its erected position wherein the legs are at right angles or substantially at right angles to the load-supporting top or whether the said pair is in its folded position wherein the legs lie along the underside of the sheet 2. The ring 26 and flange or skirt 30a serve as bearings for the bolt.

The hole 31 is provided on its edge which is further from the corresponding frame end and is at right angles to the sheet 2, with an outwardly extending ear 33 and the tapered. nose of the bolt abuts and rides along the said ear as the pair of legs is swung to its erected. position; as a consequence, the metal bracket on each leg is urged against that arm ofv the corresponding keeper plate which seats on the frame end so as to enhance the rigidity of the pair of legs relative to the loadsupporting top and to ensure that the said top is supported steadily when both pairs of legs are erected.

The bolt 24 is connected to the handled lever 18 by a link 34 and the bolt 25 is connected to the lever 19 by another similar link 35. Further, the lever 19 is provided with a laterally projecting stud 36 which projects above and through the plane of the pivoted side of the handle 22, and a roller 37 is disposed around the said stud.

When the pair of legs is locked in one or other of its alternative positions, the roller 37 is spaced from the said handle side (-see Figure 3) so that when the handle is depressed by hand to swing the lever 18 in the direction which pulls the link 34 and withdraws the bolt 24 from the corresponding keeper plate, the tapered nose of the said bolt is removed, wholly or partially, from the hole 31 (or 32) in the said plate, before the handle makes contact with the roller; thereupon, by continuing the swinging movement of the handled lever, the lever 19 is also swung in the direction which pulls the link 35 and withdraws the nose of the bolt 25 out of engagement with its corresponding keeper plate, so that the pair of legs may be swung about the pivots 11 by the hand used to depress the handle, from the one to the other of its alternative positions. When the handled lever is released as the pair of legs reaches the alternative position, the springs 28 drive the bolts automatically into engagement with their respective keeper plates and, acting through the links 34, 35, return the two levers to their initial positions. During such spring-driven return movement, the bolt 25 leads. the bolt 24 and completes its spring-driven stroke before the latter bolt so that during the final return movement .of the lever 18, the handle moves out of contact with the roller. This final movement of the handled lever ensures that both bolts are free to complete their plate-engaging, springdriven movements independently of one another so that in the erected position of the pair of legs, their tapered noses abut the respective ears 33 and both legs are held firmly and securely against the corresponding arms of the locking plates which seat upon the frame end. Also, during the said independent return movement of the bolts, any play which may develop between either leg and keeper plate due to normal wear and tear, is taken up automatically by an increase in the spring-driven travel of the bolts which causes the bolt noses 29 to move further across the ears 33.

I claim:

l. A table having a load supporting top and two pairs of legs, means for pivoting each one of the pairs of legs independently of the other pair and to the underside of the table, a cross-rail interconnecting the two legs of each of the pairs, each rail being formed between its ends with a recess and with two longitudinal passages extending in opposite directions from the recess, through the rail, to and through the legs, a bolt disposed in each of. said passages, two separate, levers pivoted on each rail, each lever being connected to a corresponding one of the bolts, one of the levers being provided with a lateral stud and the other of the levers on each rail being movable about its pivot to withdraw the bolt connected thereto into its passage and after initial movement to engage the said stud and move the other of the levers about its pivot to withdraw the bolt connected thereto into its passage, resilient means for returning the bolts individually and independently of one another to project ends of the said bolts beyond the legs, and means fixed to said table top for engaging said projecting ends in either of two positions relative to said top.

2. A table as claimed in claim 1 wherein said other lever on each rail is of inverted U-section, one of the arms of the U being pivoted to the rail, being connected to a bolt and being arranged to abut the stud on the other lever when the said U-section lever is swung about its pivot, the other arm of the said U-section being slidable in aslot formed in the rail.

3. A table having a load supporting top, a rectangular frame secured to the underside of said top, a block secured in each corner of said frame, three pockets formed in each block in the face adjacent the other block at that end of said frame, a metal keeper plate secured to each block and having two arms of which one covers said pocketed face and the other extends along the frame towards the said other block, said covering arm being formed with three holes which register respectively with the three pockets and with an car which extends into a lower of the three pockets on the side thereof inwardly of the table top periphery, said other arm being formed with an car which extends from adjacent the table top inwardly of said periphery, two pairs of legs each pair inter-connected by a cross-rail formed with a pair of coaxial longitudinally extending passages, a U-shaped bracket secured to each leg, the arms of said U-shaped bracket extending along the cross-rail towards the other leg of the pair, a pin provided on each bracket, the two pins on each pair of legs being co-axial, and projecting away from the legs into upper and outer ones of the three pockets in the corresponding block, and through the said keeper plates so as to pivotally connect each pair of legs between a pair of the blocks and to the table top, ,a hole formed in each bracket between the said pin thereon and the free end of the leg, said longitudinally extending passages in the rail each opening through a one of said legs and to said bracket holes, a bolt disposed in each passage, resilient means for urging said bolts independently and individually outwards of said passages and through said holes into ones of said pockets, and asingle lever on each rail for withdrawing the bolts in that rail into said passages successively and subsequently synchronously, so that the bolts may be withdrawn from the upper and inner pockets in the blocks and the legs swung to an erected position whereupon the bolts engage in the lower recesses in the blocks.

4. A table as claimed in claim 3 wherein the legs abut against said other arms of each keeper plate when in the erected position, each bolt is formed with a tapered nose which seats against a pocket extending ear of the said plate in the said position, the legs abut against said ears on said other arms when the legs are in the ,folded position and the hole formed in each Ll-shaped bracket is provided with a peripheral skirt which forms a bearing for the bolt extending therethrough.

5. A table as claimed in claim 3 wherein two diagonally opposed blocks are wider than the other two diagonally opposed blocks and the legs adjacent the said wider blocks lie between the two legs of the other pair when the legs are in the folded position. r

6. A table having a load supporting top and two pairs of legs, means for pivoting each pair of legs to the underside of said table independently of the other pair of legs, a cross rail interconnecting the two legs of each of said two pairs of legs, each rail being formed with two longitudinal passages extending in opposite directions through the rail and to and through said legs, a bolt disposed in each of said passages, two separate levers pivoted on each rail, one of said levers having a lateral projection, each of said levers being connected to a corresponding one of said bolts, the other of said levers on each rail being separately and freely movable about its pivot to with-,

References Cited in the file of this patent UNITED STATES PATENTS Gramelspachcr May 5, Butt Mar. 9, Hallawell Feb. 13, Symmonds Sept. 3, McMahan Oct. 15, De Saussure Aug. 31, Brown Mar. 1, Mitchell Dec. 5, Olson Nov. 6, Henry et a1 Sept. 23, Mugler Aug. 25, 

